Respiratory infections in animals, characterized by coughing or other symptoms, have been recognized for a long time. Such infections may be particularly common when non-vaccinated animals are housed in high-density circumstances. They are known to be caused by, for example, herpesvirus, calicivirus or influenza viruses, with and without other organisms that can affect or complicate such respiratory infections. Such conditions generally have not been directly mortal, although they can lead to more severe infections and death.
Influenza viruses known to infect one family of animals are not typically capable of infecting other families of animals. However, a respiratory disease has recently been observed infecting racing greyhounds, which resulted in the death of a number of dogs. In January of 2004, Dr. Cynda Crawford reportedly began investigating greyhound deaths at a racetrack in Jacksonville, Fla., where 24 greyhounds contracted the disease and 8 died. Dr. Crawford reported that the dogs, having no natural immunity to the virus, were all infected if they were exposed to the virus, and 80% of the infected dogs developed symptoms. She also reported the virus to be an H3N8 flu, which is closely related to an equine flu strain. See New York Times.com, Sep. 22, 2005. See also, Crawford, P. C., et al., “Transmission of Equine Influenza Virus to Dogs,” Science, 310, pp. 482-85 (Oct. 21, 2005).
U.S. Patent Application No. 60/673,443, filed Apr. 21, 2005 and Ser. No. 11/409,416, filed Apr. 21, 2006, and international patent application no. PCT/US2006/015090, filed Apr. 21, 2006 (published as WO06/116082), (all of which are herein incorporated by reference in their entirety) also describe Dr. Crawford's work with equine influenza viruses that infect canines. U.S. Patent Application No. 60/779,080, filed Mar. 3, 2006 (and herein incorporated by reference in its entirety) describes the use of equine influenza viruses as vaccines against influenza in canines.
There is a need for vaccines and methods for protecting any given species of animal from influenza viruses that can infect other species of animals. The following disclosure describes vaccines and methods that are generally suitable for addressing this need.